Full-Text Screening in Systematic Reviews: Best Practices and Tools

Importance of Full-Text Screening in Systematic Reviews

Full-text screening serves several crucial purposes in systematic reviews:

• Verification of Study Relevance: It allows researchers to go beyond the limited information provided in titles and abstracts to thoroughly assess whether a study truly aligns with the review's research question and scope.
• Ensuring Methodological Rigor: By examining the full text, reviewers can critically appraise the study's design, methodology, and quality to ensure it meets the required standards for inclusion. Full-text screening plays a vital role in minimizing bias by allowing for a detailed evaluation of study methodology and quality, ensuring that the included studies are robust and reliable3.
• Minimizing Selection Bias: Independent screening by multiple reviewers helps reduce the risk of bias in study selection, promoting objectivity and transparency in the review process2.
• Enhancing the Quality of Evidence Synthesis: Including only high-quality and relevant studies strengthens the evidence base for the review's conclusions and recommendations.
• Outcome Reporting: It's crucial to avoid excluding studies solely because they lack complete outcome data, as this can introduce bias. While such studies might not be suitable for meta-analysis, their implications should be considered.

The Full-Text Screening Process

Full-text screening typically involves the following steps:

1. Retrieve Full-Text Articles: Reviewers obtain the full text of all articles that were not excluded during the initial title and abstract screening phase. EviSynth automatically adds PDFs of open access articles, while others can be manually uploaded or imported in bulk using reference managers.
2. Independent Screening: Two or more reviewers independently assess each full-text article against the predefined inclusion and exclusion criteria.
3. Document Screening Decisions: Reviewers record their decisions (include, exclude, or maybe) for each article and provide clear reasons for exclusion. Documenting exclusion reasons is essential for transparency and for generating the PRISMA flow diagram, which visually represents the study selection process.
4. Resolve Disagreements: In cases of discrepancies between reviewers, a third reviewer may be consulted to adjudicate or the reviewers may discuss and reach a consensus2. In some cases, reviewers might contact study authors for further information to clarify eligibility.

Best Practices for Full-Text Screening

To ensure a rigorous and reliable full-text screening process, researchers should adhere to established best practices:

• Develop a Comprehensive Screening Protocol: A detailed protocol should outline the inclusion and exclusion criteria, screening procedures, and conflict resolution mechanisms.
• Pilot Test the Screening Process: Before starting the full-scale screening, it is advisable to pilot test the protocol with a small sample of articles to identify any ambiguities or inconsistencies.
• Use Standardized Screening Forms: Standardized forms can help ensure consistency in the application of criteria and facilitate data extraction.
• Maintain a Clear Record of Decisions: A clear record of all screening decisions, including reasons for exclusion, should be maintained for transparency and accountability.
• Regularly Calibrate Reviewers: Periodic discussions and calibration exercises can help maintain consistency in the application of criteria and minimize reviewer bias.

Challenges in Full-Text Screening

Full-text screening can be a challenging process, and researchers may encounter various obstacles:

• Reviewer Bias: Individual reviewers may have unconscious biases that can influence their screening decisions.
• Complex Criteria: Applying complex inclusion and exclusion criteria can be challenging and may require careful judgment.
• Time Constraints: Screening a large number of full-text articles can be time-consuming, especially when resources are limited.
• Inconsistent Decisions: Differences in interpretation of criteria or study details can lead to inconsistencies in screening decisions between reviewers.

Strategies for Overcoming Screening Challenges

To address the challenges inherent in full-text screening, researchers can employ various strategies:

• Mitigate Reviewer Bias: Implement blinding procedures to prevent reviewers from seeing each other's decisions until they have completed their independent assessments.
• Address Complex Criteria: Provide clear and concise definitions for each inclusion and exclusion criterion to minimize ambiguity and ensure consistent application.
• Overcome Time Constraints: Utilize tools and technologies that can streamline the screening process and improve efficiency.
• Resolve Inconsistent Decisions: Regular meetings and discussions among reviewers can help identify and address inconsistencies in decision-making.

Tools and Technologies for Full-Text Screening

Various software tools and platforms can assist researchers in managing and streamlining the full-text screening process. These tools offer features such as:

• Automated Workflow Management: Streamlining the screening process by automating tasks such as assigning articles, tracking progress, and generating reports.
• Collaborative Review Platforms: Facilitating collaboration among reviewers by providing a shared workspace for screening and discussion.
• Decision Tracking and Conflict Resolution: Recording screening decisions, identifying discrepancies, and providing mechanisms for resolving conflicts.
• Data Extraction and Analysis: Supporting data extraction and analysis by providing tools for organizing and summarizing extracted information. Researchers can utilize reference management tools like Zotero and systematic review software like EviSynth to manage citations and streamline the screening process.